Electronic components are usually subjected to certain tests in order to check their electrical functions. For this purpose a plurality of possible options have become known. For example the electronic components can be tested on the substrate before they are individualised. Or a carrier is provided on which a multiplicity of the electronic components are attached.
The carrier or substrate is then transferred to a so-called handler. The handler normally comprises a stationary testing head, with which a similarly stationary testing base is connected. The carrier or substrate is accurately positioned relative to the testing base. A testing base can be used, which makes contact with and tests all the electronic components at the same time, or only certain groups of components are tested at the same time, or each component is even tested individually. If not all the electronic components are tested at the same time the carrier or substrate must be repositioned after each step in the test.
In certain cases, however, electronic modules are also individually transferred to a handler and are processed further there individually. Here the individual components are inserted into a so-called nest and in the latter are positioned relative to the testing base.
Electronic components have become known that can switch and conduct high currents. Such components are required, for example, in power supplies for facilities with a high power demand, rapid switching intervals and the lowest possible losses.
For the high current testing of such an electronic component testing bases are often used that have two contact springs for some of the contact surfaces of the electronic component with which contact is to be made. Here one of the contact springs serves to subject the electronic component to the switching signal, and the other serves to supply the current to be switched.
Since both contact springs make contact with a single contact surface, they must be arranged relatively close to one another. On the other hand they require a high current carrying capacity. Here therefore, the small building space that is available is in conflict with the requirement for a diameter being as large as possible with a surface area being as large as possible for high current carrying capacity and good heat dissipation.
Contact springs of known art are produced from spring metal sheet and accordingly have two equal lateral faces, while their thickness is everywhere constant. The thickness of the spring metal sheet is dependent in particular on the separation distance and the size of the contact surfaces of the electronic component. In electronic components with very many, small contact surfaces located close together accordingly contact springs with a low thickness must be used, since otherwise the contact springs arranged side-by-side would affect one another or would even contact one another. As a result of the conflicting requirements of size and current carrying capacity conventional contact springs for the high current testing of electronic components with many contact surfaces located close together in particular usually have only a low service life.
The spring force of the contact springs is determined on the one hand by their material thickness and on the other hand by the minimum thickness of the spring arm. Since the spring force should always be approximately dimensioned to be the same, in the case of contact springs with a greater material thickness the said minimum thickness of the spring arm is chosen to be smaller than in the case of contact springs with a lesser material thickness.